1. Field of the Invention
The present invention concerns computer memory storage systems and, more particularly, magnetic data read/write apparatus for computer hard disk memories.
2. Description Of The Prior Art
Hard disk memories have become one of the more commonly used systems to store large quantities of data in computers. Typically between 20 million and 160 million bits of data can be stored on a single disk about five inches in diameter. Hard disk memories usually include a rigid disk, coated with a magnetic recording material, and one or more read/write heads disposed over the opposing flat surfaces of the disk to either impress a magnetic field onto a segment of the disk as data is "written" or to sense the polarization of an existing magnetic field as data is "read" from the disk.
In operation, the disk commonly spins at very high speeds with the read/write head floating on a boundary layer of air a few millionths of an inch above the disk surface. The read/write head is normally flexibly attached to a pivoting arm disposed adjacent the disk. Pivotal motion of the arm moves the position of the read/write head with respect to the center of the disk, thus affording the head coverage of the entire surface of the spinning disk. Typically electrical signals are sent to and received from the read/write head through several leads that are attached to the positioning arm. These leads commonly terminate in a pre-amplifier circuit. In order to allow the head to track variations in the disk surface while maintaining an optimum spacing between the read/write head and the disk, the end of the arm from which the head is suspended typically weighs as little as possible while still maintaining a desired stiffness. The read/write leads are also commonly made from an extremely fine, low-mass wire.
In some applications, such as mid-sized mainframe computers, several hard disks are employed together. The disks are commonly mounted on a single spindle and rotate in unison. The associated read/write heads are similarly mounted on a common positioning device so that all of the heads pivot in unison. Typically these multiple read/write heads are attached to individual lightweight suspension arms which are in turn mounted onto a more sturdy unitary positioner structure. A pre-amp circuit is also normally attached to this unitary positioner.
While suitable for accessing a large amount of data quickly, computer memory storage devices employing hard disks suffer from some drawbacks. Normally a pair of read/write heads are employed with each disk, and each read/write head commonly has three leads. Thus where eight disks operate in unison, sixteen read/write heads are normally employed along with forty-eight leads. Usually the individual read/write leads are then soldered onto the pre-amp circuit attached to the unitary positioner structure. Attaching all of these leads to the pre-amp circuit, however, is commonly a time intensive project that easily results in mis-wiring. Additionally, the fine, low-mass leads to the read/write heads are easily damaged. A small loop, called a service loop, must normally be maintained at the ends of the leads adjacent the read/write heads. Manipulation of the leads while attaching them to the pre-amp circuit can damage the service loops, requiring re-working of the minute connections between the individual leads and the read/write heads. During assembly, it is not uncommon to damage as many as ten percent of the service loops, resulting in costly and labor-intensive repair of the read/write heads.
Thus there still exists a need for a magnetic data read/write apparatus, suitable for use with hard disks, that permits the use of low-mass read/write leads while avoiding the disadvantages of the prior art. The present invention solves this need.